1. Field of the Invention
This invention relates to incineration apparatus and in particular to such apparatus having a large combustion chamber with a single burner in which the temperature gradient is quite large.
2. Prior Art
Incineration apparatus is known in which an industrial effluent is introduced in order to reduce pollution by breaking down its components to simpler and harmless gases. Some such incineration apparatus uses the principle of thermal regeneration so that the heat generated in the combustion or oxidation chamber is largely recovered before the decomposed effluent is drawn out and into the exhaust stack. One such thermal regeneration system is illustrated in U.S. Pat. No. 3,895,918 issued to James H. Mueller on July 22, 1975. In that system, a number of heat-exchange sections are arranged about and in communication with a central, high-temperature chamber. Each heat exchange section includes a heat-exchange bed of a large number of refractory elements made of ceramic or the like ("stones") confined by inward and outward perforated retaining walls. The effluent to be purified is applied to an inlet duct ring which has branch ducts that distribute the effluent to selected ones of those heat exchange sections whenever their respective associated inlet valves are opened. In such apparatus, the effluent is made to traverse the heat-exchange bed which may have a front-to-back temperature gradient by virtue of the heat generated in the central combustion chamber with which it communicates.
The combustion chamber itself may be quite large with a single burner located toward its bottom. As a result, the temperature in the chamber is quite uneven with the chamber being cooler towards its top and warmer at the bottom where the burner is. Thus, it is possible that some of the effluent drawn through the heat-exchange chamber into the combustion chamber may not come up to the requisite temperature for substantially complete oxidation of its components so that some of these incompletely burned compounds may go out of the stack with the rest of the exhaust.
One possible remedy is to use several burners distributed at various points throughout the combustion chamber. However, this is a relatively expensive solution inasmuch as each burner requires its own set of valves, controls, heat sensors, and the like. Moreover, the presence of several burners does not insure uniformity of heat in the chamber. Rather, there will be created several zones with varying temperature gradients in the chamber. Furthermore, each burner will require its own supply of ambient combustion air which is relatively cool compared with the desired temperature within the oxidation chamber.
It is therefore among the objects of the present invention to provide a system for insuring greater heat uniformity and hence greater thermal efficiency of the heat incineration apparatus, especially in large volume apparatus.
Another object of the present invention is to help to minimize the emission into the air of incompletely oxidized industrial effluents.
Still another object of the invention is to provide a uniform-heat-distribution incinerator at a cost lower than alternative approaches.
A further object of the invention is to provide incineration apparatus wherein the thermal efficiency of the system is enhanced by reduction of the use of ambient combustion air in alternative multi-burner systems.
Other objects of the invention will be apparent to those skilled in the art upon perusal of the drawings, specification and claims in this case.